The invention relates to a missile launcher for use on a military aircraft, comprising means for moving the missile away from the aircraft before the propulsion unit of the missile is ignited.
Missile launchers are already known comprising two actuating jacks or cylinders whose pistons exert forces which move the missile away from the aircraft when the cylinders are fed from a source of pressurized fluid which may be a liquid or, more frequently, combustion gases, as described for instance in French Specification No. 2,498,747.
By using a missile launcher of this type and igniting the missile propellent once the missile is at a distance from the aircraft, it is possible to house the missile partially within the fuselage, thereby reducing the aerodynamic drag, and/or to mount several missiles in tandem under the fuselage. However, the prior art constructions have a defect which becomes very serious if ignition of the propellent charge takes place a considerable time after ejection: a relative difference as low as 1/100 between the forces exerted by the two cylinders is sufficient to impart to the missile an appreciable angular pitch speed. Since it is extremely difficult to balance the forces exerted by the cylinders with such a degree of accuracy, the attitude of the missile at ignition of the propellant cannot be accurately adjusted.
It is an object of the invention to provide an improved launcher for ejecting a missile. It is a more specific object to provide a launcher which imparts a well defined angular pitch velocity to the missile for the whole ejection range, thus allowing ignition of the propellent unit and operation of the control means to be delayed. It is still another object to provide greater operating safety by mechanically preventing ejection of the missile as long as a prior unlocking operation has not taken place and to increase the degree of error acceptable as to the position of the center of gravity.
According to the invention, there is provided a missile launcher comprising, on a supporting structure: releasable means for securing the missile; a bearing shoe on the missile connected to the supporting structure by links articulated so as to form a deformable quadrilateral, approximately a parallelogram; and fluid pressure controlled means for successively releasing the securing means and actuating the links in a direction causing the shoe to push the missile away, said shoe having a sufficient length for determining not only the distance between the missile and the aircraft but also the angular position of the missile. With this arrangement, the position and angular speed of the missile when the thrust of the shoe ceases may be accurately determined. The angular speed is substantially zero when the links form a deformable parallelogram. On the other hand, a link system having a shape different from a parallelogram may rotate the shoe during its movement, and so the angular pitching ejection speed of the missile can be adjusted. In particular, it is possible to give to the missile a nose down (or tail down) position and a pitching speed so as to move the missile rapidly away from the aircraft and so as to take into account conditions under which firing generally takes place.
The shoe will advantageously be provided with a shape which mates with the shape of the skin of the missile; it may have a length representing at least one sixth of the length of the missile and be placed so as to exert its action on the missile in the zone of the center of gravity thereof. However, a missile launcher according to the invention may tolerate appreciable variations in so far as the dimensions, mass an position of the center of gravity are concerned.
The means for securing the missile typically comprises a rail in one or more pieces, along which one or more fittings of the missile are slidably received. Then the missile may be inserted by forwarly moving it until it is longitudinally retained by a locking hook, movable by an actuating cylinder so as to drive the missile forwards and to free the fittings from the rail. In a first embodiment, the unlocking cylinder comprises a movable assembly which, during a first part of its path from a rest position, causes disengagement of the missile and, during a second part, causes ejection by actuation of the shoe. In another embodiment, the fluid pressure means comprise a first cylinder for unlocking and a second cylinder which controls the movement of the shoe, the two cylinders being associated by fluid transfer means arranged so that the second cylinder can only be actuated after the first has caused unlocking.
The invention will be better understood from the following description of particular embodiments given by ways of examples.